The present invention relates to the conveying of articles to a machine in which it is desired to maintain the build-up of articles ahead of the machine at approximately constant length. More particularly, this invention concerns a regulator system used in conjunction with machines that are being continuously supplied with containers, such as bottles or the like, by a conveyor, for regulating the rate of machine operation in response to the magnitude of container accumulation at the machine inlet.
In the case of machines which handle containers, such as by filling, sealing, capsuling, and/or labeling the containers for example, it is necessary to adapt the speed of machine operation in order to establish sufficiently high capacity, dependent of course on which type of container is being filled. On the other hand, reliability of machine operation often requires at least some degree of container accumulation at the machine inlet so that containers are continuously available for treatment. Both of these problems could be solved through a special system regulating the speed of the machine to establish high capacity, while being capable of subjecting the machine to a change of conveyor flow (i.e. container feeding), thereby influencing the corresponding container accumulation.
Up to now there has been utilized an unstable two-point regulation wherein control elements of digital operation are installed ahead of the machine. These control elements can be located either on the conveyor, or on a transversal guide in the case of a multiple-laned conveyor. Signals emanate from the control elements to regulate machine speed. This method of regulation generally results in the speed drive being operated often. Over-charge conditions may occur, with container accumulation taking up relatively long sections of the transport chains.
It is an object of the present invention to eliminate or minimize such problems.
Another object of the present invention is to regulate the operating speed of an article-handling machine in accordance with forces produced by accumulated articles, such as containers that are being fed to the machine.
Another object of this invention is to change the machine operating speed in response to changes in the size of article accumulation so that variation of the operating speed maintains the accumulation at nearly a constant level.
A further object is to enable such maintained level of accumulation to be easily adjusted.